Merck secures FDA breakthrough status for Calderasib and Keytruda lung cancer combination

Merck (NYSE:MRK) announced Friday that the U.S. Food and Drug Administration has granted Breakthrough Therapy designation to its investigational oral drug calderasib when paired with the company’s blockbuster immunotherapy Keytruda, accelerating its development path for newly diagnosed lung cancer patients.

The regulatory milestone applies to the first-line treatment of patients with advanced or metastatic non-small cell lung cancer (NSCLC) whose tumors harbor a specific KRAS G12C genetic mutation and express the biomarker PD-L1 with a tumor proportion score of 1% or higher.

Known as MSD outside the United States and Canada, the New Jersey-based pharmaceutical giant noted that this marks the first Breakthrough Therapy designation awarded to calderasib, which is also identified as MK-1084.

The FDA’s decision was supported by preliminary clinical data from the ongoing Phase 1 KANDLELIT-001 trial.

The combination strategy pairs an oral targeted inhibitor designed to block a specific mutated protein that drives tumor growth with an anti-PD-1 therapy that unleashes the patient's own immune system to detect and fight cancer cells.

The therapeutic development holds significant weight for oncology pipelines because the KRAS G12C aberration represents one of the most frequently observed mutations in lung malignancies.

It occurs in approximately 14% of patients diagnosed with NSCLC adenocarcinoma, a major subtype of the disease.

The FDA reserves its Breakthrough Therapy designation for experimental treatments intended for serious or life-threatening conditions where preliminary clinical evidence suggests the drug could offer a substantial improvement over existing standard-of-care options.

By achieving this status, Merck becomes eligible for intensified regulatory support, including continuous, early-stage guidance from the FDA on efficient clinical trial frameworks.